Some embodiments relate generally to methods and apparatus for dynamic distributed provisioning in a network including, for example, provisioning of network resources by network devices. Some embodiments relate more specifically to providing distributed provisioning of virtual computing resources by network devices such as access switches in a switch fabric within a data center.
Virtualized environments or enterprises such as those in data centers include virtual computing resources or virtual machines that execute or are hosted on physical servers. Multiple virtual machines can be hosted by a single physical server. Virtual machines can be configured to perform most functions that physical servers perform. Use of virtual machines can be beneficial for, for example, efficient use of physical computing resources, fault tolerance of physical computing resources, and continued service during maintenance of physical computing resources.
Virtual machines can also introduce additional complexity in a network environment. For example, to provide fault tolerance of physical computing resources, virtual machines typically migrate or are transferred from a first server to a second server. In large-scale network environments such as, for example, data center environments, migration of virtual machines typically involves provisioning or configuration of network ports and/or network devices such that network traffic is routed from the first server to the second server after the migration. Some known network management solutions pre-provision the network ports and/or devices in the network. Although pre-provisioning addresses the need to provision network ports and/or devices after migration of a virtual machine, it can result in inefficient usage of forwarding path resources. For example, pre-provisioning includes defining or reserving IP addresses before they are used, processing data packets at network switches for virtual resources that are not operatively coupled to those network switches, and forwarding network traffic to network ports (or virtual ports) that are not yet connected to a particular virtual machine. Additionally, this situation can be a security concern because network traffic can be forwarded to network ports on servers with no virtual machine or service active at those network ports.
Other known network management solutions rely on complex management and policy orchestration tools to manage migration and provisioning of network ports and/or devices. Such known tools typically provision the network ports and/or devices based on a description of the network topology provided a priori by a system administrator. These known tools typically rely on such a description to determine which network ports and/or switches will be provisioned after migration of a virtual machine. Such descriptions can be difficult to compile, maintain, and verify, resulting in additional complexity for the network administrator and significant opportunities for misconfiguration of network ports and/or devices. Additionally, because such descriptions are provided a priori, such tools can impose static requirements on the topology of networks. Thus, a need exists for improved, dynamic provisioning in networks.